Bottom-hole shut-in tool



May 7, 1968 D. R. MCLELLAND BOTTOM-HOLE SHUT-IN TOOL 3 Sheets-Sheet 1 Filed 061;. 31, 1966 POW E/R SUPPLY CONTROL UNIT FIG. I.

ATTORNEY- if A 5 Sheets-Sheet 3 ATTORNEY.

May 7, 1968 D. R. MCLELLAND BOTTOM-HOLE SHUT-IN TOOL Filed Oct. 31, 1966 3,381,751 BOTTOM-HOLE SHUT-1N TOOL Donald R. McLelland, Houston, Tex., assignor to Esso Production Research Company Filed Oct. 31, 1966, Ser. No. 590,838 8 Claims. (Cl. 166-65) The present invention concerns a well pipe plug or shut-in tool suspendible on an electrical conductor cable in a well and capable of sealing oif fluid pressures from below. More particularly, the invention relates to a well pipe plug provided with means controllable from the surface for setting and releasing the plug.

This shut-in tool is especially adaptable for use with pressure bomb or transducer apparatus designed to measure transient flow test (pressure buildup or falloff test) data. Interpretation of such data is often difficult because of after-flow effects. The improved bottom-hole shut-in tool of this invention prevents most of the after-flow (a small amount of after-flow will still take place because of gas saturation around the well bore) and thereby avoids measurement of much of the meaningless data taken in transient fiow tests.

A shut-in tool of this type is preferably capable of repeated operations without coming out of the hole. Further, such tools should be set and released without movement, jarring, etc, of the line on which it is suspended to avoid damage to pressure bombs or transducers, which has occurred in the past. The tool of the present invention meets these requirements.

Therefore, a primary object of the present invention is to provide an improved shut-in tool which is suspendible in the borehole on an electrical conductor cable which tool is self-generating in energy, capable of repeated operations without being withdrawn from the hole, and which is set and released without jarring action or other movement of the cable on which the tool is suspended.

Briefly, the apparatus of this invention for plugging a well pipe comprises a housing; a mandrel movable relative to said housing; rotatable means connected to said housing; pipe-gripping means connected to said housing adapted to be forced into pipe-gripping engagement with the interior of said well pipe upon movement of said mandrel in one direction relative to said housing and to be released from pipe-gripping engagement with the interior of the well pipe upon movement of said mandrel in an opposite direction relative to said housing; an expansible packer means arranged on said mandrel adapted to be expanded to seal off fluid pressure in said well pipe upon movement of said mandrel in said one direction relative to said housing and to retract and release said well pipe seal upon movement of said mandrel in an opposite direction relative to said housing; releasable locking means initially preventing movement of said mandrel in said one direction relative to said housing; compression means arranged in said mandrel adapted, when compressed, and upon release of said locking means, to move said mandrel in said one direction relative to said housing and force said pipe-gripping means into pipe-gripping engagement and to expand said packer into engagement with said well pipe wall; means arranged on said rotatable means and connected to said mandrel movable in response to rotation of said rotatable means to cause said compression means to compress when said rotatable means is rotated in one direction and to permit said compression means to expand from a compressed condition when rotated in a reverse direction; and means arranged in said housing adapted to rotate said rotatable means clockwise and counterclockwise, rotation of said rotatable means in one direction causing said compression means to compress and said locking means to release States Patent c ce and rotation of said rotatable means in an opposite direction causing said compression means to expand and said locking means to lock said mandrel in position.

The above object and other objects and advantages of the invention will be apparent from a more detailed description thereof when taken with the drawings where- FIG. 1 is a view in longitudinal section through a borehole illustrating a shut-in tool constructed in accordance with the present invention; and

FIGS. 2-5 are views in longitudinal section showing the shut-in tool of the invention in various stages of operation.

Referring to the drawings in greater detail, in FIG. 1 a shut-in tool generally designated 10 is suspended in a well pipe 12 on an electrical conduct-0r cable 13. The upper end of cable 13 traverses a sheave 14 and is connected to a winch 15. Leads from conductor cable 13 connect to a surface control unit 16 which is connected to a power supply 17 for operating the tool and recording units. As seen in FIG. 1, tool 10 includes an upper housing 20 to which are connected pipe-engageable slips 21 adapted to be forced outwardly to engage the inner wall of well pipe 12 by engagement with the cone or Wedge surface 22, which is connected to a lower housing or mandrel 23 movable relative to housing 20 and is provided with .a rubber packer or sealing member 24 which expands to seal olf the space between well pipe 12 and mandrel 23 when mandrel 23 moves upwardly relative to housing 20.

As seen in FIGS. 2-5, housing 20 contains a reversible DC motor 25 connected to 'a gear reduction box 26 in its upper end. A rotatable shaft 27 provided with screw threads 28 to form a worm gear on its lower end extends from gear box 26 into mandrel 23. A travelling nut 29 threaded on worm gear 28 is keyed to grooves 30 formed in the interior of mandrel 23 by means of lugs 31. A power spring 32 is arranged in mandrel 23 supported at its lower end on the upper side of travelling nut 29 and at its upper end by a shoulder 33 formed on the upper end of mandrel 23.

A locking sleeve 35 having an enlarged upper end 36 tapering at an intermediate section 37 to a smaller end portion 38 surrounds shaft 27. In the running in and running out of the well position of the tool, with the pipegripping elements and packer element retracted, tapered section or shoulder 37 engages a tapered annular shoulder 39 on the upper end of mandrel 23. A light compression spring 51 causes a downward bias on locking sleeve 35. The interior of the lower end of housing 20 is provided with ball-retaining indentations or grooves 40, an annular seal 41 and slip-retaining shoulder members 42. The upper end of mandrel 23 is provided with ballretaining openings 43. The plurality of slips 21 are sup ported on housing 20 at their upper ends 45 by shoulder 42. A spring 46 biases slips 21 to their retracted positions.

A packer element 24, preferably made of resilient reinforced rubber, is secured at its upper end to a slidable collar 48 having a wedge-shaped surface or cone-shaped surface 22 on which slips 21 are adapted to slide. The lower end of packer element 24 is secured to mandrel 23.

In operation, tool 10 is lowered in well pipe 12 on electrical conductor cable 13 to a level at which it is desired to operate the tool. The shut-in tool is run in well pipe 12 in the position shown in FIG. 2. Positive DC current from power supply 17, applied to DC motor 25 and through gear reduction box 26 used to obtain additional power and slower speed from motor 25, rotates shaft 27 and worm gear 28 in a clockwise direction. Clockwise rotation of worm gear 28 forces travelling nut 29 to move upwardly and compress power spring 32. Continued clockwise rotation causes travelling nut 29 to contact and move locking sleeve upwardly, the upper enlarged portion 36 of which holds a plurality of steel locking balls 50 in their indentations or grooves in housing 20. Such movement as seen in FIG. 3 permits locking balls to fall out of indentations 40 in housing 20 which triggers power spring 32 and frees mandrel 23 for upward movement relative to housing 20. FIG. 3 shows the position of the parts of the tool at the instant of release of balls 50 before power spring 32 biases lower housing 23 upwardly.

Upon release of the locking balls and their disengagement from grooves 40 in housing 20, power spring 32 being fully compressed forces mandrel 23 upwardly into housing 20 quickly. This snap action movement forces slips 21 to cam outwardly as they slide on the cone or wedge surface 22 and engage the well pipe, as illustrated in FIG. 4.

Continued upward movement of mandrel 23 under the bias of spring 32 causes packer element 24 to expand outwardly, as upward movement of slidable collar 48 is stopped by slips 21, and seal against the wall of well pipe 12 thus effecting a shut-in of the well at the depth of the tool, as shown in FIG. 5.

Additional power supplied to motor 25 and additional resulting rotation of shaft 27 and worm gear 28 causes I the power spring 32 to be further compressed to provide added force to eifect the seal. Once the tool is set in the position illustrated in FIG. 5, differential pressure across the tool tends to aid in maintaining the seal.

Following completion of the pressure test, negative DC current is applied to motor 25 causing shaft 27 and worm gear 28 to rotate in a counterclockwise direction thereby forcing travelling nut 29 downwardly. When power nut 29 reaches the lower end of its travel in grooves 30, continued counterclockwise rotation of worm gear 28 moves mandrel 23 downwardly. Such movement causes packer element 24 to retract to equalize pressure across the tool and permit slips 21 to release and retract under the bias of spring 46. Continued negative current application and counterclockwise rotation of worm gear 28 returns the tool to the original position shown in FIG. 2.

The invention is not to be considered restricted to the specific details set forth above as various modifications thereof may be made without departing from the spirit and scope of this invention.

Having fully describde the objects, advantages, apparatus and mode of operation of my invention, I claim:

1. Apparatus for plugging a well pipe comprising:

a housing;

a mandrel movable relative to said housing;

rotatable means connected to said housing;

pipe-gripping means connected to said housing adapted to be forced into pipe-gripping engagement with the interior of said well pipe upon movement of said mandrel in one direction relative to said housing and to be released from pipe-gripping engagement with the interior of the well pipe upon movement of said mandrel in an opposite direction relative to said housing;

an expandable packer means arranged on said mandrel adapted to be expanded into engagement with said well pipe wall to seal off fluid pressure in said well pipe upon movement of said mandrel in said one direction relative to said housing and to retract and release said well pipe seal upon movement of said mandrel in an opposite direction relative to said housing;

releasable locking means initially preventing movement of said mandrel in said one direction relative to said housing;

compression means arranged in said mandrel adapted upon release of said locking means to move said mandrel in said one direction relative to said housing and force said pipe-gripping means into pipe-gripping engagement and to expand said packer means into engagement with said well pipe wall;

means arranged on said rotatable means and connected to said mandrel movable in response to rotation of said rotatable means to cause said compression means to compress when said rotatable means is rotated in one diretcion and to permit said compression means to expand from a compressed condition when rotated in a reverse direction; and

means arranged in said housing adapted to rotate said rotatable means, rotation of said rotatable means in one direction causing said compression means to compress and said locking means to release, and rotation of said rotatable means in an opposite direction causing said compression means to expand and said locking means to lock said mandrel in position.

2. Apparatus as recited in claim 1 in which said movable means arranged on said rotatable means includes means threadedly mounted on said rotatable means and keyed to grooves formed in said mandrel.

3. Apparatus as recited in claim 2 in which said compression means includes a spring surrounding said rotatable means supported between said means threadedly mounted on said rotatable means and one end of said mandrel.

4. Apparatus as recited in claim 3 in which said releasable locking means includes locking ball members initially positioned in grooves formed in said housing and a locking sleeve surrounding said rotatable means and engagable with said means threadedly mounted on said rotatable means.

5. Apparatus as recited in claim 4 in which said pipegripping means includes slips supported on said housing and a movable cam surface arranged on said mandrel engaging said slips.

6. Apparatus as recited in claim 5 in which said movable cam surface member is slidably arranged on said mandrel adapted to expand said packer means upon movement of said manderl.

7. Apparatus as recited in claim 6 in which said means to rotate said rotatable means includes a reversible electric motor connected to said rotatable means.

8. Apparatus as recited in claim 7 in which said means threadedly mounted on said rotatable means includes a traveling nut.

References Cited UNITED STATES PATENTS 1,406,350 2/1922 Corrigan 166-65 2,076,314 4/1937 Zschokke 16665 2,217,986 10/1940 Knox 166125 2,245,712 6/1941 Ragan 166-65 2,399,766 5/1946 Steward 166-65 JAMES A. LEPPINK, Primary Examiner. 

1. APPARATUS FOR PLUGGING A WELL PIPE COMPRISING: A HOUSING; A MANDREL MOVABLE RELATIVE TO SAID HOUSING; ROTATABLE MEANS CONNECTED TO SAID HOUSING; PIPE-GRIPPING MEANS CONNECTED TO SAID HOUSING ADAPTED TO BE FORCED INTO PIPE-GRIPPING ENGAGEMENT WITH THE INTERIOR OF SAID WELL PIPE UPON MOVEMENT OF SAID MANDREL IN ONE DIRECTION RELATIVE TO SAID HOUSING AND TO BE RELEASED FROM PIPE-GRIPPING ENGAGEMENT WITH THE INTERIOR OF THE WELL PIPE UPON MOVEMENT OF SAID MANDREL IN AN OPPOSITE DIRECTION RELATIVE TO SAID HOUSING; AN EXPANDABLE PACKER MEANS ARRANGED ON SAID MANDREL ADAPTED TO BE EXPANDED INTO ENGAGEMENT WITH SAID WELL PIPE WALL TO SEAL OFF FLUID PRESSURE IN SAID WELL PIPE UPON MOVEMENT OF SAID MANDREL IN SAID ONE DIRECTION RELATIVE TO SAID HOUSING AND TO RETRACT AND RELEASE SAID WELL PIPE SEAL UPON MOVEMENT OF SAID MANDREL IN AN OPPOSITE DIRECTION RELATIVE TO SAID HOUSING; RELEASABLE LOCKING MEANS INITIALLY PREVENTING MOVEMENT OF SAID MANDREL IN SAID ONE DIRECTION RELATIVE TO SAID HOUSING; COMPRESSION MEANS ARRANGED IN SAID MANDREL ADAPTED UPON RELEASE OF SAID LOCKING MEANS TO MOVE SAID MANDREL IN SAID ONE DIRECTION RELATIVE TO SAID HOUSING AND FORCE SAID PIPE-GRIPPING MEANS INTO PIPE-GRIPPING ENGAGEMENT AND TO EXPAND SAID PACKER MEANS INTO ENGAGEMENT WITH SAID WELL PIPE WALL; MEANS ARRANGED ON SAID ROTATABLE MEANS AND CONNECTED TO SAID MANDREL MOVABLE IN RESPONSE TO ROTATION OF SAID ROTATABLE MEANS TO CAUSE SAID COMPRESSION MEANS TO COMPRESS WHEN SAID ROTATABLE MEANS IS ROTATED IN ONE DIRECTION AND TO PERMIT SAID COMPRESSION MEANS TO EXPAND FROM A COMPRESSED CONDITION WHEN ROTATED IN A REVERSE DIRECTION; AND MEANS ARRANGED IN SAID HOUSING ADAPTED TO ROTATE SAID ROTATABLE MEANS, ROTATION OF SAID ROTATABLE MEANS IN ONE DIRECTION CAUSING SAID COMPRESSION MEANS TO COMPRESS AND SAID LOCKING MEANS TO RELEASE, AND ROTATION OF SAID ROTATABLE MEANS IN AN OPPOSITE DIRECTION CAUSING SAID COMPRESSION MEANS TO EXPAND AND SAID LOCKING MEANS TO LOCK SAID MANDREL IN POSITION. 